Dennis F. Evans facts for kids

Dennis Frederick Evans was a brilliant English scientist. He made big discoveries in chemistry, especially about how magnets affect chemicals and how we can study atoms using a special technique called nuclear magnetic resonance.

Early Life and Learning

Dennis Evans was born in Nottingham, England, on March 28, 1928. His father, George Frederick Evans, was a skilled carpenter. His mother, Gladys Martha Taylor, was a dressmaker.

Dennis was a very bright student. He went to Huntingdon Street Junior School. Then, he won a special scholarship to attend Nottingham High School. In 1946, he earned another scholarship to Lincoln College at Oxford University. There, he was taught by a famous chemist named Rex Richards.

In 1949, Dennis won the university's Gibbs Prize in Chemistry. That same year, he started working on his advanced degree (DPhil) with Rex Richards. They studied how much heat chemicals produced and the magnetic properties of certain materials. This work led to many important scientific papers. He also did research at the University of Chicago, studying how light interacts with chemicals.

Amazing Discoveries in Chemistry

In 1955, Dennis Evans became a lecturer in chemistry at Imperial College London. He was promoted several times, eventually becoming a Professor in 1981. In the same year, he was also made a Fellow of the Royal Society (FRS), which is a very high honor for scientists.

Dennis was interested in many different areas of chemistry. Here are some of his most important contributions:

Measuring How Magnetic Things Are

Some materials are slightly attracted to magnets. This property is called "magnetic susceptibility." Knowing this can be very helpful for scientists.

In 1959, Dennis Evans invented a clever way to measure this. It's now called the Evans Method. He used a special machine called an NMR machine. He would put the magnetic chemical in a tube with another simple chemical. The magnetic chemical would slightly change the signal of the simple chemical in the NMR machine. By looking at this change, he could figure out how magnetic the first chemical was.

He also improved an older method called the Gouy balance. Instead of weighing the chemical in a magnetic field, he weighed a small, strong magnet against the chemical. This made the measurements even more accurate.

Using Nuclear Magnetic Resonance (NMR)

Besides using NMR to measure magnetic properties, Dennis Evans used this technique a lot to study complex chemicals. NMR is like taking a "fingerprint" of a molecule. It helps scientists understand how atoms are connected in a chemical. He used it to study special compounds that contain metals.

New Ideas in Inorganic Chemistry

Dennis Evans also made discoveries in inorganic chemistry, which studies chemicals that don't mostly contain carbon. He was very creative in this area. For example, he showed that some rare metals, like samarium, europium, and ytterbium, could behave like special chemicals called Grignard reagents. These Grignard reagents are very useful for building new and complex molecules.

A Life Full of Surprises

Dennis Evans was a very kind and helpful person. He loved sharing his vast knowledge with anyone who asked. He knew a lot about many things, not just chemistry!

He was also famous for keeping unusual pets. He had an alligator from the Cayman Islands and a five-foot-long sand snake named George. George liked to eat live toads! One time, George escaped onto a busy street, the King's Road. After he was caught, Dennis gave George to the London Zoo. Dennis also kept locusts (some of which escaped too!), lizards that ate birds, and giant scorpions. He was a well-known member of the Chelsea Arts Club, a place where artists and creative people gather.